class_docstr: Test FASTALoader
code: def test_legacy_fasta_one_hot(self):
      input_file = os.path.join(self.current_dir, "example.fasta")
      loader = dc.data.FASTALoader(legacy=True)
      sequences = loader.create_dataset(input_file)
  
      # example.fasta contains 3 sequences each of length 58.
      # The one-hot encoding turns base-pairs into vectors of length 5 (ATCGN).
      # There is one "image channel".
  
      assert sequences.X.shape == (3, 5, 58, 1)
  
file_path: deepchem/deepchem/data/tests/test_fasta_loader.py
imports: import os
  import unittest
  import deepchem
  from deepchem.feat.molecule_featurizers import OneHotFeaturizer
label_desc: Use image node_id 2 for calling the TestFASTALoader obj's underlying member method code with example usage: obj.test_legacy_fasta_one_hot() without return types